DBA – MySQL, PostgreSQL, MongoDB, Oracle
Background: For the oracle errors like “ORA-12170: TNS:Connect timeout occurred”, “ORA-12535: TNS:operation timed out”, “ORA-12560: TNS:protocol adapter error”, “TNS-00505: Operation timed out” and like others related to oracle listener it is useful of tracing the listener activities to dig down further. Workaround: Connect to the listener control utility from the command line or shell. LSNRCTL…
Background: For the purpose of taking backup of the MS access database, VBA script failed for one of the tables of the source database, showing “Property not found Error: 3270“. Resolution: Compact and repairing didn’t solve the issue, recreated the table also didn’t help. Upon further dig down its been observed that removing the “Calculated”…
Background When you create a virtual machine in VirtualBox the virtual machine or OS needs internet or the virtual machine and your physical machine need to talk to each other or the virtual machine need to be reached from other computers from the network and vice-versa. These are done by VirtualBox networking which uses its…
Background Cloning of a virtual machine is the easiest way around to get the copy of the same operating system environment which saves time and effort of another installation and configuration of the same. Workaround Choose the virtual machine that should be cloned. Right click on the VM and select “Clone”. Provide the “Name”, “Path”…
Background Individuals working in the soft engineering like database, software, development, quality assurance more often needs to deploy & configure different things which need to have an Operating System obviously and sometimes more. With the advent, maturity and easy to get virtual technologies like VirtualBox, Vmware and Parallels Desktop and others it is easier to…
It’s pretty easy to install any application or software in Windows operating system but what about Unix/Linux based system? Mostly Unix/Linux based operating systems are built to serve Enterprise or Production applications not intend to serve day to day End User tasks. As a result there are more coding/scripting stuffs than automation in case of…
What is an EIP? An ECS in cloud environment gets its networking ability provided by VPC which is a private network, means you can’t talk to other world except your own private network nodes. To access the outer world that is the internet you should apply and bind an EIP(Elastic IP) to your ECS. How to:…
What is an ECS? ECS stands for Elastic Cloud Server that facilitates computing needs for applications, technically it is a virtual machine in cloud environment. Steps to create an ECS: Determine the resource required like cpu, memory and storage. Determine the Operating System images with required version. For networking create a VPC if not already…
Before creating a Tenant we should know what is a Tenant in OpenStack or in Huawei Fusion Cloud? A Tenant is a project in OpenStack that use to isolate resources in a cloud environment and the users of the allocated resources. Cloud environment consists of a pool of various resources and you create tenants to…
Background: I need email functionality to send emails from the web server by querying data from MySQL database and email the result to appropriate recipient. Workaround: Install sendmail. sudo apt-get update sudo apt-get install sendmail Install mailutils. sudo apt-get install mailutils Configure the /etc/hosts file, provide your domain name in the following format 127.0.0.1 localhost…
Background: Based on the considerations of requirements, controls, budgets and performance you may wish to migrate your WordPress website/blog from your current hosted service provider to amazon EC2 instance. I have migrated one of my website to the amazon EC2 and like to share my experience so it may help others. The migrated website was…
Background: Amazon EC2 instance assigned with a public and private ip address. The public ip address changes when the instance stopped and started again but not when the instance restarted. Due to this nature service is prone to interruption if the instance stopped for maintenance and started again. Workaround: Amazon offers the Elastic IP for…
Background: WordPress is currently the most popular platform for creating websites. One can build his website in WordPress on shared hosting service or in dedicated servers. Both means have their advantages and disadvantages, like when you use shared hosting service you have your environment ready, you will only work in your website/blog having little control…
After you have launched your Amazon EC2 Linux instance it’s time to connect to it. You can connect it through a standalone SSH client like BitVise SSH client or PuTTY. Here we will use bitvise SSH client to connect to EC2 Linux installation. Requirements: Private Key file(.pem) downloaded during Launch of your EC2 instance. …
Developing or deploying applications over cloud infrastructure made life easy for the professionals. Amazon public cloud offers computing solution named as EC2 which is easy to deploy with the options to select from a pool of operating systems. Amazon cloud services are offered in a wide variety of price ranges from low to high. On…
Background For the IGW application testbed preparation we need the schema export and then be imported. When export initiated by Data Pump EXPDP the oracle error showed up. UDE-22303: operation generated ORACLE error 22303 OCI-22303: type “SYS”.”KU$_STATUS1020″ not found Workaround Upon investigating in the alert log file the below lines are showing up indicating a…
Background: After shutdown and restarted the oracle instance by an executive, client can’t connect to database instance though database is up and running and listener service is up. OS: Windows Server 2012 x64, Oracle: 11g R2, Data Guard Configured Workaround: From the alert_SID.log file found the below error raised after shutdown and consecutive startup and when…
Background: All of a sudden importing data from spreadsheet in a form produced the above error(it was tested and worked fine over two weeks), the same operation in another form is executing fine. This is bit frustrating when everything seems fine, no errors in logic or elsewhere but things are not working. Solution: Digging down further…
Background: Generally we use ctrl+c to quit any task in windows command prompt or ctrl+z in Unix flavors. For oracle data pump exports/imports this is not the case when you type any of them, ctrl+c or ctrl+z actually pause the job and closing the command or shell window doesn’t quit the oracle data pump job…